Conventional telephone networks comprise a plurality of telephone switching systems interconnected by telephone links, principally trunks, and sometimes lines. The links carry telephony traffic (or calls) and traffic-related (or call-associated) signaling between the switching systems. The switching systems normally have no capability to communicate control information to each other, apart from the call-associated signaling.
If it is desired to communicate additional control information between the switching systems, they must be interconnected by a data network. But the construction and provision of an additional network is expensive. Nor are all of the capabilities of a full-fledged separate data network typically needed. All that the switching systems usually require are the following three features:                1) The ability, at all times, of near-instantaneous broadcast,        2) of small amounts of data,        3) From one switching system to all others.        
To avoid the need for a separate data network, the art has developed the temporary signaling connection, or TSC. The TSC uses non-call-associated signaling across telephone links to implement a data network. However, the TSC provides only point-to-point communications capability, and this requires that each pair of nodes that wish to communicate with each other be connected by a direct link. Moreover, each node must keep a database of information that defines the web of links that connect the node to other nodes and indicates which link connects to which remote node. Both of these characteristics make the TSC impractical for networks comprising more than a few nodes.